Quantum Dots
What they are: Precisely manufactured microscopic crystals.
What they do: Transform the light emitted by LED backlights to produce a wider range of colors.
How they improve the picture: Typical LCD TVs aren't able to display all of the colors in the current standard for broadcast television, much less the much wider standard that's being pushed for future broadcasts. Quantum dots broaden their color spectrum.
Also called: LG's name for it is ColorPrime, and Samsung labels it SUHD. Sharp and Panasonic are also promising a wider color range in their new TVs, but their Spectros and Wide Color Phosphor technologies don't use quantum dots.